Chilean state copper producer Codelco and state owned subway firm Metro signed an agreement on Thursday to supply copper for the new lines 3 and 6of the underground transportation service in capital Santiago.

All the handrails at the new stations will be made of antimicrobial copper, which prevents the growth of bacteria and will minimize infections for subway users, Metro's president Raphael Bergoeing said at the ceremony to sign the agreement.

The ceremony was held at the Santiago Bueras subway station, which was inaugurated at the end of January as part of an 8.6km expansion to line 5. It is the first subway station in the world to use handrails made of copper, and served as the pilot project for the agreement, Codelco's CEO Diego Hernández said.

The copper handrails required a total investment of 98mn peso (US$203,425). Codelco contributed with copper alloy tubes for the handrails, worth 9mn pesos and equivalent to 1.15t of copper, while Metro invested 89mn pesos in the manufacture and installation of the handrails. Codelco also provided technical advice for the manufacturing of the pieces, Hernández said.

The handrails at Santiago Bueras totaled 350m and the new stations are estimated to need 10,000m.

The construction of the new subway lines will be officially announced by Chilean President Sebastián Piñera shortly, according to Bergoeing.